Changes in kernel/generic/src/ddi/ddi.c [77429d3:d7533c7] in mainline

File:

• kernel/generic/src/ddi/ddi.c (modified) (5 diffs)

kernel/generic/src/ddi/ddi.c

@@ -104 +104 @@
 {
         ASSERT(TASK);
-        ASSERT((pf % FRAME_SIZE) == 0);
-        ASSERT((vp % PAGE_SIZE) == 0);
-        
-        /*
-         * Make sure the caller is authorised to make this syscall.
-         */
-        cap_t caps = cap_get(TASK);
-        if (!(caps & CAP_MEM_MANAGER))
-                return EPERM;
+        
+        if ((pf % FRAME_SIZE) != 0)
+                return EBADMEM;
+        
+        if ((vp % PAGE_SIZE) != 0)
+                return EBADMEM;
+        
+        /*
+         * Unprivileged tasks are only allowed to map pareas
+         * which are explicitly marked as such.
+         */
+        bool priv =
+            ((cap_get(TASK) & CAP_MEM_MANAGER) == CAP_MEM_MANAGER);
         
         mem_backend_data_t backend_data;
@@ -123 +127 @@
         
         if (znum == (size_t) -1) {
-                /* Frames not found in any zones
-                 * -> assume it is hardware device and allow mapping
+                /*
+                 * Frames not found in any zone
+                 * -> assume it is a hardware device and allow mapping
+                 *    for privileged tasks.
                  */
                 irq_spinlock_unlock(&zones.lock, true);
+                
+                if (!priv)
+                        return EPERM;
+                
                 goto map;
         }
         
         if (zones.info[znum].flags & ZONE_FIRMWARE) {
-                /* Frames are part of firmware */
+                /*
+                 * Frames are part of firmware
+                 * -> allow mapping for privileged tasks.
+                 */
                 irq_spinlock_unlock(&zones.lock, true);
+                
+                if (!priv)
+                        return EPERM;
+                
                 goto map;
         }
@@ -138 +155 @@
         if (zone_flags_available(zones.info[znum].flags)) {
                 /*
-                 * Frames are part of physical memory, check if the memory
-                 * region is enabled for mapping.
+                 * Frames are part of physical memory, check
+                 * if the memory region is enabled for mapping.
                  */
                 irq_spinlock_unlock(&zones.lock, true);
@@ -150 +167 @@
                 if ((!parea) || (parea->frames < pages)) {
                         mutex_unlock(&parea_lock);
-                        goto err;
+                        return ENOENT;
+                }
+                
+                if (!priv) {
+                        if (!parea->unpriv) {
+                                mutex_unlock(&parea_lock);
+                                return EPERM;
+                        }
                 }
                 
@@ -158 +182 @@
         
         irq_spinlock_unlock(&zones.lock, true);
-        
-err:
         return ENOENT;